作者：庞清乐, 何辰斌, 马兆兴, 郑杨, 叶林

作者单位：青岛理工大学信息与控制工程学院, 山东 青岛 266000

关键词：三电平中点钳位逆变器;模型预测控制;故障穿越;微电网;孤岛运行

摘要：

随着新能源和微电网的高速发展，孤岛状态下逆变器的故障穿越能力显得尤为重要。针对现有控制方法下孤岛中点钳位（neutral point clamped，NPC）逆变器故障穿越能力弱的问题，提出基于模型预测控制的孤岛微电网NPC逆变器故障穿越控制方法。通过比较负载电压与参考电压实现故障高速诊断；通过提高故障相参考电流幅值提升故障相电流；通过划定计算扇区、消除冗余计算减少计算量和避免权重系数设计；为保证电能质量以及减小数据测量和算法计算产生的延时，采用两步预测方法对延时进行补偿。在Matlab/Simulink中搭建三相LCL孤岛NPC逆变器仿真模型，仿真结果表明，该控制方法在孤岛微电网正常运行时能够将三相电流THD均值控制在2%以内，发生故障时，对故障相电流THD值控制在4%以内，对非故障相电流THD值控制在1.5%以内，能够有效提升孤岛NPC逆变器的故障穿越能力。

Research on fault ride through control method of NPC inverter in island microgrid based on model prediction
PANG Qingle, HE Chenbin, MA Zhaoxing, ZHENG Yang, YE Lin
School of Information and Control Engineering, Qingdao University of Technology, Qingdao 266000, China
Abstract: With the rapid development of new energy and Microgrid, the fault ride through ability of inverter in island state is particularly important. Aiming at the problem of weak fault ride through ability of isolated point clamped (NPC) inverter under the existing control methods, a fault ride through control method of isolated microgrid NPC inverter based on model predictive control is proposed. High speed fault diagnosis is realized by comparing load voltage with reference voltage. The fault phase current is increased by increasing the reference current amplitude of the fault phase. By delimiting the calculation sector, eliminating redundant calculation, reducing the amount of calculation and avoiding the design of weight coefficient. In order to ensure power quality and reduce the delay caused by data measurement and algorithm calculation, a two-step prediction method is used to compensate the delay. The simulation model of three-phase LCL Island NPC inverter is built in Matlab / Simulink. The simulation results show that the control method can control the average value of three-phase current thd within 2% in normal operation of isolated island microgrid, control the value of fault phase current thd within 4% in case of fault, and control the value of non fault phase current thd within 1.5%, which can effectively improve the fault ride through capability of isolated island NPC inverter.
Keywords: NPC inverter;model predictive control;fault ride through;microgrid;island operation
2023, 49(9):180-187  收稿日期: 2022-6-21;收到修改稿日期: 2022-8-29
基金项目: 山东省自然科学基金资助项目（ZR2020ME194）
作者简介: 庞清乐（1969-），男，山东聊城市人，教授，硕士生导师，博士，主要研究方向为智能配电网故障检测与控制、分布式电源并网控制等。
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